How so, I hear you ask?
Well, 12:00 am is twelve ante meridiem, twelfth hour before midday, right? What time is that? …Correct!
Now, 12:00 pm is twelve post meridiem, twelfth hour after midday. What time is that now? …Correct again!
Clearly, then, whether 12:00 am and 12:00 pm, it’s still midnight!
So, how do you indicate “twelve noon” I hear you ask again?
Well, “twelve noon” should actually be denoted by “12:00 m”, because, after all, “m” refers to meridiem, midday that is!
Confused by this “m” in “12:00 m”? You think “12:00 m” might be misinterpreted as “twelve midnight”?
OK, as an ultimate concession and gesture of good will, I will let you substitute “m” by its equally deserving and much less recognized nasal sibling “n”, to have “12:00 n” stand for “twelve noon”. Use 12:00 am, 12:00 pm, or just 12:00 for midnight. (You are not going to confuse “12:00 n” for “twelve at night”, are you?)
Simple, logical, and unequivocal?
Afterword: Now you know, beyond any doubt, that these old unprogrammed programmable VCRs were flashing 12 midnight…